Wondering about Gun pressures w/bases & Universal Clear

EDP

EDP

Promoted Users
Sorry for the long post, still trying to learn.

Reading threads about spraying UC vs Euro as well as trying to figure out proper pressures for base coats. The UC threads talk about spraying at about 28psi at the gun & 150 on the wall. I just figured out how to increase my pressure switch on the Eaton compressor, its a single stage 80 gal w/a max 175 PSi rating so I cranked it to 150ish...

Just bought a new Devilbiss touchup gun that I shot UC with last night on the engine bay repairs at 16 psi, seemed to work fine, sprayed the Pro-spray base @ 10, that went on fine too - the gun itself says "30 PSI max inlet", my LPH 400 says 10 PSI on the cap...

All the pressure differences get a little confusing & obviously the viscosity differences require or work better with different pressures, clear, base , primer, etc.. but for a novice its a bit daunting to remember. Wondering if are there rules of thumb to simplify this that I can apply to each product & adjust from there?
 
EDP said:
the gun itself says "30 PSI max inlet"
Click to expand...
That's just so it is compliant meaning EPA compliant in regulated areas. 10 PSI at the cap is the max for EPA regulated areas. All this has to do with air quality not how your gun will spray. DO a search there are a lot of threads on this here.
 
makes sense now, not thinking like that when Im reading the tech sheet or looking at the guns. The touchup gun sprayed base pretty well at 16 psi...
 
Another thing that many overlook is the CFM requirements of the spray gun. PSI is the pressure rating and CFM is the volume of air needed at that pressure.

All spray guns have a required amount of both stated. Notice the Chart below for a DeVilbiss Tekna Copper and look at the last two column.
1635952216085.png


Recommend inlet pressure is the PSI setting with Air Flow is the required CFM (SCFM) at that pressure.
Your compressor needs to put out that much volume of air (and preferably a bit more) in order to properly supply the spray gun with air.

I have the 7E7 HE tips for mine so the 1.4 tip requires 11 CFM at 22 PSI.
 
Remember, air pressure for a touch-up gun is totally different than air requirements for a full-size gun, like you found out.
Click to expand...
Your right, I did find out! That little gun worked pretty good @ 16 psi, I remember shooting UC in the past & I had notes for my LPH that said 28#'s at the gun & 100 on the wall. Then I read some posts recently about running the wall pressure at 150 but I couldnt get my line pressure any higher than 120 as the diaphram on my Sharpe dessicant filter wouldn't go any higher, thats when I called Eaton and learned how to adjust the pressure switch on the comp.

when I bought that comp. 10 yrs ago I remember looking at all the SCFM values and it was appropriate for painting and all scavenge needs, then I completely forgot about all that!

will a hose ID make a huge difference ? 1/4" vs 3/8"
 
You must log in or register to reply here.
Back
Top